DESCRIPTION: (Adapted from applicats abstract) The objectives of this study are to scientifically evaluate dietary fiber therapy for fecal incontinence and to determine a course of fiber supplementation that will reduce fecal incontinence and potentiate the effectiveness of other adjuvant therapies. Fecal incontinence is an embarrassing and often debilitating problem that interferes with the quality of life and makes care difficult. Fecal incontinence can precipitate depression and isolation and increase functional dependence and the likelihood of placement in a nursing home. Investigation of the causes of fecal incontinence is in the early stages, and current treatments, including invasive surgical procedures, are often inadequate. Since fecal incontinence is exacerbated by liquid stools, current conservative medical management utilizes bulking-type dietary fiber to reduce the liquid consistency of stools. These bulking fibers are only partly fermented by colonic bacteria and are thought to sequester stool water in an unfermented fiber-stool matrix. An alternate therapeutic approach is to use a highly fermentable dietary fiber whose metabolic byproducts, short chain fatty acids (SCFAs), may increase the absorption of stool water by the colon and thus improve continence. This pilot study will determine and compare the effects of a conventional, bulking-type fiber supplement that is partially fermented, a fiber supplement that is completely fermented and a placebo in adults who are incontinent of loose/liquid stools. A randomized, controlled, single- blind clinical trial using a pretest-posttest control group design will be used. The specific aims are: (1) to determine and compare the effects of a fiber supplement that is partially fermented, completely fermented, and a placebo on the percentage of water content of stools, stool consistency, and percentage of incontinent stools; (2) to determine and compare the effects of a fiber supplement that is partially fermented, completely fermented, and a placebo on the concentration and utilization of fecal SCFAs and pH of stool fluid in fecally-incontinent adults; and, (3) to determine and compare the effects of a fiber supplement that is partially fermented, completely fermented, and a placebo on the amount of unfermented fiber in stools of fecally-incontinent adults. The long- term goal is to determine the optimal regimen of fiber supplementation to reduce or eliminate fecal incontinence in adults. This study will provide a basis for the investigation of the use of dietary fiber supplements to improve the outcomes of adjunctive therapies such as biofeedback. In addition, this study will provide preliminary data for future investigations of the colonic mechanisms involved in reducing fecal incontinence.